guided practice - ABS Community Portal

EXAMPLE 4
on p. 181
for Exs. 42–47
184
PROBLEM SOLVING
42. PIZZA SPECIALS At a pizza shop, two small pizzas, a liter of soda, and a salad
cost $14; one small pizza, a liter of soda, and three salads cost $15; and three
small pizzas and a liter of soda cost $16. What is the cost of one small pizza?
of one liter of soda? of one salad?
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43. HEALTH CLUB The juice bar at a health club receives a delivery of juice at the
beginning of each month. Over a three month period, the health club received
1200 gallons of orange juice, 900 gallons of pineapple juice, and 1000 gallons
of grapefruit juice. The table shows the composition of each juice delivery.
How many gallons of juice did the health club receive in each delivery?
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Juice 1st delivery 2nd delivery 3rd delivery
Orange 70% 50% 30%
Pineapple 20% 30% 30%
Grapefruit 10% 20% 40%
44. MULTI-STEP PROBLEM You make a tape of your friend’s three favorite TV
shows: a comedy, a drama, and a reality show. An episode of the comedy
lasts 30 minutes, while an episode of the drama or the reality show lasts
60 minutes. The tape can hold 360 minutes of programming. You completely
fill the tape with 7 episodes and include twice as many episodes of the drama
as the comedy.
a. Write a system of equations to represent this situation.
b. Solve the system from part (a). How many episodes of each show are on
the tape?
c. How would your answer to part (b) change if you completely filled the
tape with only 5 episodes but still included twice as many episodes of the
drama as the comedy?
45. ★ TAKS REASONING The
following Internet announcement describes the
results of a high school track meet.
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5 WORKED-OUT SOLUTIONS
on p. WS1
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a. Write and solve a system of equations to find the number of athletes who
finished in first place, in second place, and in third place.
b. Suppose the announcement had claimed that the Madison athletes scored
a total of 70 points instead of 68 points. Show that this claim must be false
because the solution of the resulting linear system is not reasonable.
5 TAKS PRACTICE
AND REASONING